Women can have around 20 kids in their life time. Take my aunt for example, 13 children.

Men can impregnate thousands of women. So from the start of our evolution women were bound to play a more important role in surviving. That's why, women and children go first.

if there were only 1,000,000 men and 1 woman left in the world, our species would be pretty hard pressed to repopulate. However if there were 1 man and 100 women left... we could repopulate the earth relatively quickly. So long as the one man lived long enough to impregnate all the women. Which most likely wouldn't be a problem. And if the man lived long enough for each woman to have 20 kids that would be 2,000 individuals in 20 years. Where as the other way around the human population would probably be in perpetual decrease, as it's likely at least 2 men would die for every 1 child born. Followed by a severe population loss and equaling out to about 20-30 individuals.